A vehicle seat unit of the prior art is found in Japanese Unexamined Patent Publication No. 2002-96663. FIG. 7 shows the vehicle seat unit disclosed in this Unexamined Patent Publication No. 2002-96663, in which FIG. 7A shows a condition that enables an occupant to be seated, FIG. 7B shows a condition where a seat cushion 90 has been swung to an upright position by lifting its rear end, and FIG. 7C shows a condition where the rear end of the seat cushion 90 has been turned frontward from the condition of FIG. 7B down to an approximately horizontal position and, after sliding seat rails rearward, a seatback 91 has been turned frontward (to a reversed position).
Specifically, when a lever 92 of a lock mechanism provided in the seatback 91 is operated in the condition of FIG. 7A, a cable 93 is pulled, a latch (not shown) provided at the seat bottom to fix the seat cushion 90 in position is disengaged from a striker 94 and, then, the rear end of the seat cushion 90 is turned upward by a spring (not shown) provided at a seat front bracket 95. Subsequently, the seat cushion 90 is turned frontward down to the approximately horizontal position with the aid of its own weight according to the Publication.
However, the seat cushion 90 is normally considerably heavy as it incorporates a frame unit (not shown) to prevent deformation of the seat cushion 90 and to give a comfortable ride. For this reason, it is necessary to exert a great force when turning the seat cushion 90 from its reversed position shown in FIG. 7C to the position of FIG. 7B (as shown by an arrow) in the construction of the aforementioned Unexamined Patent Publication No. 2002-96663, resulting in poor operability. Operability is further worsened by two-step operation involving the need to turn up the seatback 91 and then the seat cushion 90.
In light of the foregoing, it is an object of the invention to reduce the amount of force needed for turning a seat cushion from its approximately horizontal position to a position where an occupant can be seated on a seat unit by operating the seat cushion, thereby achieving an improvement in operability.